This invention relates to a device for inspecting the external appearance of medicine such as a tablet, a capsule, a pellet or other objects (hereinafter referred to as "solid medicine") to determine whether it is acceptable or not.
Heretofore, the external appearance of such solid medicine has only been visually inspected. However, this technique suffers from problems in that the classifying capability is lowered because of fatigue, and the classification standard fluctuates because of the differences in human selection criteria. Furthermore, in association with increasing personnel expenses and the requirement for increasing the inspection speed, there has been a strong demand for mechanically carrying out this inspection.
In carrying out the external appearance inspection of solid medicine by the use of a mechanical means, the mechanical system should satisfy the following conditions:
(a) Solid medicine is automatically and smoothly supplied;
(b) At least one surface of a piece of solid medicine and the opposite surface (in the case of a capsule, the upper half surface and the lower half surface thereof when laid) are automatically observed;
(c) Even in the case where one surface of a piece of solid medicine is different in external appearance from the opposite surface (for instance in the case where only one of the two surfaces of a solid medicine has marks, or in the case where the color of one surface is different from that of the opposite surface), the external appearance thereof can be positively inspected; and
(d) The device is simply constructed and the maintenance and inspection thereof can be readily achieved.
If the piece of solid medicine is small, it is, in general, difficult to simultaneously observe both surfaces thereof to meet the requirement (b). In this case, after one surface thereof has been observed, it is necessary to use a paticular device to turn over the piece to observe the opposite surface. In this connection and in view of requirement (c), a device which may give mechanical vibration or impact to the solid medicine cannot be utilized as the solid medicine turning over means. Stated differently, the results of observation of two surfaces of solid medicine must be combined in the general determination. Therefore, there should be no possibility that when solid medicine is turned over, it interchanges place with another, or it is transposed to a position where no solid medicine has been placed.
Conventional external appearance inspecting devices of this type have been investigated from the above-described criteria, however, no device satisfying the conditions (a) through (d) fully has not been proposed or has reached the point of commercial acceptance.